Vulnerability in Handlebars-lang Handlebars.js
CVE-2026-33939
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. `{{*n}}`), the compiled templa…
EPSS: 0.001 (22.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Handlebars-lang Handlebars.js — versions >= 4.0.0, < 4.7.9
Weakness classification (CWE)
References
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-9cx6-37pm-9jff (x_refsource_CONFIRM)
- https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2 (x_refsource_MISC)
- https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9 (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-33939?
- CVE-2026-33939 is a high-severity vulnerability in Handlebars-lang Handlebars.js, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.5/10. Published 2026-03-27.
- How severe is CVE-2026-33939?
- High severity. CVSS v3 base score is 7.5 out of 10.